The correct order of reactivity of the following benzyl halides towards reaction with KCN is :

'P' is

Choose the correct set of reagents for the following conversion.

Which one of the following reactions will not lead to the desired ether formation in major proportion?

(iso- $\mathrm{Bu} \Rightarrow$ isobutyl, sec $-\mathrm{Bu} \Rightarrow$ sec-butyl, $\mathrm{nPr} \Rightarrow \mathrm{n}$-propyl, $$ { }^{\mathrm{t}} \mathrm{Bu} \Rightarrow \text { tert-butyl, } \mathrm{Et} \Rightarrow \text { ethyl) } $$